St. Tammany farmer. [volume] (Covington, La.) 1874-current, 1887-04-09
SCIENCE AND INDUSTRY.

"A new silk-mill. recently started Al
Harrisburg. Pa, employs four hundred
hands.
In North Carolina it Is estimated
that forty thousand persons follow the
business Of collecting herbs for the
market.
-" BY new process Of steamins
white wood and submitting it to pres
sure, it can be made SO tough as to re-
quire coal chisel to split it.
"A scientist after . careful analysis
Of the impressions made upon the
retina by different degrees Of light.
concludes that both white and black
are colOrs. and both should have a
proper place upon the chromatic scale.
Boston Budget.
"A valuable discovery. which bids
fair to create a revolution in the ranks
of the roofer's trade, is the recent util.
izatiOn Of compressed paper pulp ~ a
substitute for slate in the manufacture
of tiles for roofing. ng.-Philadielphia Press.
Some idea of the wonderful progress
now being made in microscopical SCI
ence may be formed by the fact. as
stated by the president Of the British,
Association lately. that results are now
attained in this line which mathema-
ticians five years ago declared to be
impossible.
"A resident Of Palatka, Fla, has in
vented sewing machine that promises
to do great things. The attachment
consists Of number Of wires 20 ar
ranged that scraps of cloth are sewed
on base in a substantial manner, and
rugs, trimmings, lambrequins, etc.. can
be made very rapidly.-C1icago Times.
In some of the great sawmill estab-
lishments of the Western States circular
saws of six feet diameter are run at
about $50 revolutions per minute.
though some have been driven at speed
of $50 revolutions. When working at
$50 revolutions the teeth of the saw will
travel through nearly three miles in .
minute.
Probably no application of science
is developing more rapidly than pho
Biography. Among recent appliances is
a detective camera in the form of a
watch. with charm to hold a supply Of
miniature dry-plates, and a telescope
camera in which distant objects are
brought near BY telescope aid and
photographed.
"A French commission. appointed to
inquire into the protection Of buildings
from lightning, have reported to the
minister of instruction that it is indis-
pensable for complete safety to have all
iron roofs, doors. pipes. sashes. etc..
carefully connected with the apparatus
usually attached to public buildings as
protection against electric discharges.
Prof. F. s. Dennis. of New York.
made some experiments on q recent trip
across the Atlantic to test the purity Of
the air about one thousand miles from
land. He found that in stateroom on
the main deck the air was quite impure.
In a cabin on the promenade deck.
where the circulation was freer, it was
very much purer, while at the bow Of
the steamer it was found to be entirely
uncontaminated.-M r. Tribune.
The principle Of the zoetrope. or
wheel Of life. has recently been utilized
to show the passage Of certain isometric
crystals from one form into another.
The Transformation Of a cube. for in
stance. into an octahedron or dOdecahe-
dron, through the intermediate COM
pound forms. bv the replacement Of its
angles by planes. can be shown directly
to the student and will greatly aid him
in comprehending the primary laws Of
fOrms.-Chic100 Tribune